1. Field of the Invention
The present invention relates to air conditioning and heating systems, and more specifically to a filter rack for holding an air filter of a furnace, heat pump, air conditioner, or other type of air handler.
2. Description of Related Art
Air conditioning systems typically include an air-handler that provides conditioned air to a comfort zone, such as a room or a designated area within a building. The conditioning of the air may include, but not be limited to heating, cooling, humidifying, dehumidifying, filtering, ventilating, and their various combinations. Air handlers often include a sheet metal enclosure that contains various components, such as a blower, filter, heat exchanger, controls, etc.
Air handlers and their enclosures are preferably reconfigureable so they can be readily connected to a building""s ductwork. Depending on the application, the building""s return air duct may need to be connected to the enclosure""s right side, left side, or bottom. Thus, an enclosure may include various knockout or otherwise removable panels that allow a return air opening to be created where needed.
Creating such a return air opening often involves a significant amount of work and may require various tools for cutting, trimming, bending, screwing, etc. This can be especially true when the air handler""s return air filter is situated right at the return air opening, which is often the case. Thus, additional work may be required to relocate filter-related hardware, such as a filter rack, which holds the filter.
Once an air handler is properly configured and set up, the filter may be replaced regularly with normal maintenance. In some cases, the actual size of the replacement filter may be slightly different than that of the original filter, even though both filters may have the same nominal size. Slight differences in size may create a gap between the filter and the filter rack, which could allow return air to bypass the filter.
In some cases, the size of a filter may be adjustable, as disclosed in U.S. Pat. Nos. 6,007,596; 5,492,551 and 5,312,467. However, the price of such filters may be relatively expensive, when compared to common disposable filters. Other filter assemblies may use a spring for sealing or for various other purposes, as disclosed in U.S. Pat. Nos. 2,979,159 and 5,458,667. However, such mechanisms may not close off an air gap caused by a rectangular filter whose length or width is too short. Moreover, such mechanisms may complicate the process of reconfiguring an enclosure during the initial installation of the air handler.
To overcome the limitations of current air handler enclosures, it is an object of the invention to provide a filter rack whose side members are spring biased outward.
Another object to provide a filter rack comprising a side member that is spring biased outward and a filter rail that is spring biased inward.
Another object is to use a leaf spring to act between the side member and the filter rail.
Another object is to use an extension spring to outwardly urge the side members of a filter rack.
Yet, another object is to provide a filter rack with a movable channel for receiving filters of different widths.
A further object is to provide a filter rack with sliding end members that allow the width of the filter rack to be reduced which simplifies the installation of the rack.
A still further object is to connect an extension spring to a pair of sliding end members to urge the members to a greater length.
Another object is to spring load a filter rack into engagement with an air handler enclosure.
Another object is to provide a filter rack whose side members are movable to enable the rack to be installed within an enclosure in various orientations.
These and other objects of the invention are provided by a filter assembly that includes a filter rack adapted to hold a removable filter. The rack is a generally rectangular frame with two opposite sides that are urged apart by a spring. The spring loaded sides help hold the rack within an enclosure of an air handler.